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Samsung’s own support documentation lists 256GB as the officially supported maximum microSD capacity for the Galaxy A8 (2018) — that capacity ceiling is the one hard rule here. It doesn’t shrink the field to a handful of cards, though: SanDisk, Samsung, Lexar, Kingston, PNY, TeamGroup, Amazon Basics, Netac, and Silicon Power all currently sell 128GB and 256GB microSDXC cards, so there’s a real range from budget to premium at or under that ceiling.
| # | Product | Price | Where to buy |
|---|---|---|---|
| 1 | SanDisk Ultra 256GB microSDXC | $25-$35 | Amazon · eBay |
| 2 | Samsung EVO Select 256GB microSDXC | $27-$45 (street price; higher at full MSRP) | Amazon · eBay |
| 3 | Samsung PRO Plus 128GB microSDXC | $45-$55 | Amazon · eBay |
| 4 | Lexar PLAY 256GB microSDXC | $18-$28 | Amazon · eBay |
| 5 | Kingston Canvas Select Plus 128GB microSDXC | $22-$26 | Amazon · eBay |
| 6 | TeamGroup Elite 128GB microSDXC | $28-$32 | Amazon · eBay |
| 7 | Silicon Power Superior 128GB microSDXC | $34-$46 | Amazon · eBay |
| 8 | Netac P500 Extreme Pro 128GB microSDXC | $22-$28 | Amazon |
| 9 | Amazon Basics 128GB microSDXC | $9-$12 | Amazon · eBay |
The picks, in detail
SanDisk Ultra 256GB microSDXC
The safe, well-known choice at the A8’s documented capacity ceiling — UHS-I speed class is plenty for the A8’s camera and app storage.
- 256GB capacity
- Class 10, UHS-I, A1 rated
- Includes SD adapter
- Reliable, widely-reviewed brand
- Frequently the cheapest 256GB option in this list
- Not the fastest card here
- No high-endurance rating for constant video recording
Samsung EVO Select 256GB microSDXC
Samsung’s own-brand card, a natural pairing for a Samsung phone, with UHS-I U3/A2 speed for faster app loading and 4K video capture.
- 256GB capacity
- UHS-I, U3, A2 rated
- Waterproof and temperature-resistant
- Made by the same company as the phone
- A2 rating helps app-on-SD-card performance
- Price fluctuates more than SanDisk’s
- MSRP runs high outside of sales
Samsung PRO Plus 128GB microSDXC
A step up from EVO Select for A8 owners who want faster, more consistent write speeds — overkill for casual use, but a real option if you shoot a lot of video.
- 128GB capacity
- UHS-I, U3, A2, V30 rated, up to 180MB/s read
- Waterproof, temperature- and X-ray-proof
- Noticeably faster sustained writes than EVO Select
- Samsung’s higher-durability build
- Costs more per GB than the EVO Select
- Half the capacity of the 256GB picks unless you buy the 256GB size
Lexar PLAY 256GB microSDXC
A budget-friendly 256GB option built with Nintendo Switch and Android devices in mind, offering full capacity at a lower typical price than SanDisk or Samsung.
- 256GB capacity
- UHS-I, C10, U3, V30, A1 rated
- Rated up to 160MB/s read
- Usually the cheapest 256GB card of the group on sale
- Good rated speeds for the price
- Less brand history in phones specifically than SanDisk/Samsung
- Regular (non-sale) price is less predictable
Kingston Canvas Select Plus 128GB microSDXC
A lower-capacity option for A8 owners who don’t need the full 256GB and would rather save money — still fast enough for photos, apps, and casual video.
- 128GB capacity
- Up to 100MB/s read, A1 rated
- Includes SD adapter
- Well-reviewed budget mainstay
- Plenty of room for most users’ photo/app libraries
- Half the capacity of the 256GB picks
- Not the card to buy if you shoot a lot of 4K video
TeamGroup Elite 128GB microSDXC
A budget mainstream brand that undercuts the big names while still carrying real UHS-I/V30 speed ratings — a solid middle option between Amazon Basics and SanDisk/Samsung pricing.
- 128GB capacity
- UHS-I, U3, V30, A1 rated
- Includes SD adapter
- Cheaper than SanDisk or Samsung at the same capacity
- Real V30 speed rating, not just a Class 10 label
- Less brand recognition in the US than SanDisk/Samsung
- Fewer long-term reliability reviews than the bigger names
Silicon Power Superior 128GB microSDXC
A performance-oriented card from an established Taiwanese flash brand, with A2 app-performance rating for smoother app loading than basic A1 cards.
- 128GB capacity
- UHS-I U3, V30, A2 rated
- Includes SD adapter
- A2 rating gives it an edge in app-load speed over A1-only cards
- Established brand with a long memory-card track record
- Priced closer to premium cards than to the budget picks
- Less common in US retail than SanDisk/Samsung/Kingston
Netac P500 Extreme Pro 128GB microSDXC
A budget-to-mid card from a fast-growing Chinese flash brand, a reasonable middle ground for A8 owners who don’t want the cheapest possible card but also don’t want to pay SanDisk/Samsung prices.
- 128GB capacity
- UHS-I, up to 100MB/s read / 90MB/s write
- Includes SD adapter
- Solid rated speeds for the price
- Cheaper than the big-name equivalents
- Shorter reputation history than SanDisk/Samsung/Kingston
- Harder to find at brick-and-mortar retail
Amazon Basics 128GB microSDXC
The rock-bottom budget pick — Amazon’s own house brand, fine as a secondary card or for a phone that mostly stores photos and a modest app library.
- 128GB capacity
- A2, U3 rated, up to 100-200MB/s read depending on version
- Includes SD adapter
- Cheapest card in this entire list
- Backed by Amazon’s own return policy
- No brand pedigree in flash memory specifically
- Sold under a generic house brand, so build/binning consistency is less proven than dedicated memory brands
Buying tips
- Samsung’s support documentation for the Galaxy A8 (2018) states a 256GB maximum — some owners report success with larger cards, but that’s outside Samsung’s documented support, so this list stops at 256GB.
- A1/A2-rated cards load apps installed to the SD card noticeably faster than older cards without that rating — worth checking for on any card you buy, budget or premium.
- Format the card in the phone itself (Settings > Storage) after inserting it, rather than relying on how it was formatted at the factory.
As an Amazon Associate and eBay Partner, toptenpick.com earns from qualifying purchases. Prices and availability are subject to change.